17.8 CNS Tumors Flashcards
How do metastatic CNS tumors present?
Multiple well-circumscribed lesion
What are the cancers that metastasize to the brain?
Lung, breast and kidney cancer
Do primary CNS tumors often metastasize?
No
What is the most common CNS tumor in adults?
Glioblastoma Multiforme
Where do tumors in adults tend to occur?
Above the tentorium
Where do tumors in children tend to occur?
Beneath the tentorium
Glioblastoma Multiforme (GBM)
Malignant high-grade tumor of astrocytes
What is an important feature of GBM?
It will cross the corpus callosum
What are some histological features of GBM?
Necrosis with pseudo-palisading cells and endothelial cell proliferation
Meningioma
Most common benign tumor and is made of arachnoid cells
What gender is meningioma seen more often in?
Females
What symptom can meningiomas present with?
Seizures - mass that presses on the cortex
What is the histologic feature of meningioma?
Whorled-cells
Schwannoma
Benign tumor of Schwann cells that involves the cranial/spinal nerves
What is a very common position for Schwannoma?
Cerobellar Pontine Angle and commonly involves CN VIII
What marker is positive in Schewannomas?
S100
With what are bilateral Schwannomas seen?
Neurofibromatosis Type 2
Oligodendroglioma
Malignant tumor of oligodendrocytes that usually involves the frontal lobe and is a calcified tumor in the white matter
What can oligodendroglioma present with?
Seizures
What is the most common CNS tumor in children?
Pilocytic Astrocytoma
Pilocytic Astrocytoma
Benign tumor of astrocytes that usually arises in the cerebellum
What is seen on imaging of Pilocytic Astrocytoma?
Cyst with a neural nodule
What is seen on histology of Pilocytic Astrocytoma?
Astrocytes with thick eosinophilic processes - Rosenthal fibers
Medulloblastoma
Malignant tumor derived from granular cells of the cerebellum - neuroectodermal tissue - and is usually found in children
What is seen on histology of medulloblastoma?
Small round blue cells with Homer-Wright rosettes that may or may not be present
What is the prognosis of medulloblastoma?
Poor prognosis and the tumor grows rapidly, spreading with the CSF
Ependymoma
Malignant tumor of the ependymal cells that is usually seen in children
What area are ependymomas typically found?
4th ventricle - may present with hydrocephalus
Craniopharyngioma
Benign tumor from epithelial remnants of Rathke’s pouch that presents as a supratentorial mass in children or young adults
What can craniopharyngioma lead to?
Compression of the optic chiasm can lead to bitemporal hemianopia
